[Pd/Co-Nb/Pd/Si]多层膜的结构与磁性

用高频溅射法制备了两套Pd/Co-Nb/Pd/Si]多层膜,分别用X射线衍射和振动样品磁强计做了结构和磁性测量。随Pd层厚度增加(或Co-Nb层厚度减少),Pd层由非晶态过渡到晶态,并观察到Pd的fcc(111)双峰结构,双峰的位置逐渐从两侧向体材料Pd的fcc(111)峰的位置靠近。双峰来源于Co-Nb层与Pb层、Pd层与Si层的晶格失配度以及靠近这两种界面的Pd原子的极化不同。样品的饱和磁化强度随Pd层增厚(或Co-Nb层增厚)从小于同样成分的Co-Nb合金体材料的饱和磁化强度值单调增大到大于体材料

STRUCTURAL AND MAGNETIC PROPERTIES OF [Pd/Co-Nb/Pd/Si] MULTILAYERED FILMS

Two series of Pd/Co-Nb/Pd/Si] multilayer films were prepared by rf sputtering. The measurements of structure and magnetism were made by X-ray diffraction and magnetometer, respectively. As the thickness of Pd layers increases, the structure of Pd layers transfers from an amorphous state to a polycrystalline state. The polycrystalline state of the Pd layers shows two adjacent Pd fcc(111) peaks, which originate from the differences of lattice-mismatching degree and polarization of Pd atoms between the interfaces of Co-Nb layers and Pd layers and the interfaces of Pd layers and Si layers. As the thickness of Pd layers increases, the saturation magnetization monotonously increases from a value which is smaller than that of the bulk Co-Nb alloy with the same compositions to another value which is larger, then takes a constant value. This is contributed to the effects of polarization of Pd layers, dimension of Co-Nb magnetic layers and interdiffusion of atoms in the interfaces. The amorphous Co-Nb layers can influence the polarization of Pd atoms in the range of 2.5nm from the interfaces of Co-Nb layers and Pd layers. The is related to the strong interdiffusion of atoms in the interfaces and the large change of the Pd lattice constant in the film normal.